Question

For each pair of points below, think about the line that joins them. For which pairs is the line parallel to the y-axis? Circle your answer(s). Then, give 2 other coordinate pairs that would also fall on this line.

a. (4, 12) and (6, 12)
b. (3/5, 2 3/5) annd (1/5, 3 1/5)
c. (0.8, 1.9) and (0.8, 2.3)

Answer 1

a) Not parallel to y-axis

b) Not parallel to y-axis

c) Parallel to y-axis

Explanation:

The best way to check whether a line passing through two points is parlle to y-axis is by plotting them on graph.

The equation of line:
`(y-y_1) = (y_2 - y_1)/(x_2 - x_1)(x-x_1)`

a) The line joining the points (4,12) and ( 6,12) is not parallel to y-axis.

It is parallel to x-axis. Another two points that can lie on this line are : (5,12) and (
`(9)/(2)`,12).

b) The line joining the points
`((3)/(5), (13)/(5)), ((1)/(5) ,(8)/(5))` is not parallel to y-axis.

Equation of line:
`5y - 7.5x = 5.5`

Another points that could be lie on this line are (0.6,2) and (0.25,1.475)

c) The line joining the points
`(0.8, 1.9), (0.8,2.3)` is parallel to y-axis because points have the same x-coordinate.

Another points that could be lie on this line are (0.8,2) and (0.8,2.1)